Senate candidate Christine O'Donnell chats with voters in Wilmington, Del., on Tuesday. Ms. O'Donnell took on nine-term Rep. Michael N. Castle in the Republican primary for a U.S. Senate seat. (AP Photo)
Rep. Michael N. Castle, who has held elective office in Delaware since the mid-1980s, finds himself unexpectedly behind "tea party" favorite Christine O'Donnell in the Republican primary for the Senate. (AP Photo)
Sen. Jack Reed, Rhode Island Democrat, thinks the Senate will have a "serious debate" on the so-called Bush tax-cut extension, but he will not speculate on an agreement. House Democratic leaders say they want to see what the Senate does before acting. (Associated Press)
Associated Press photographs
West Virginia Gov. Joe Manchin III (left), a Democrat, leads in polls for a Senate seat, but his GOP rival, businessman John Raese (right), has closed the gap. One analyst calls it a "race worth watching."
Rep. Michael N. Castle, Delaware Republican, is taking his GOP rival for the nomination for Senate more seriously after a Republican senator was denied renomination by an insurgent in Alaska.
California Assemblywoman Julia Brownley, a Democrat from Santa Monica, left, talks with state Senator Christine Kehoe, a Democrat from San Diego, during the Senate debate over Ms. Brownley's bill proposing to ban use of plastic shopping bags at the Capitol in Sacramento Tuesday, Aug. 31, 2010. The measure failed.(AP Photo/Rich Pedroncelli)
Democratic Senate candidate Robin Carnahan talks to members of the media during the Governor's Ham Breakfast at the Missouri State Fair Thursday, Aug. 19, 2010 in Sedalia, Mo. (AP Photo/Charlie Riedel)
Joe Miller, Republican candidate for U.S. Senate, and his wife, Kathleen, enter election central in Anchorage, Alaska, on Tuesday. Returns showed Mr. Miller ahead of incumbent Sen. Lisa Murkowski.
Senate candidate Joe Miller has been campaigning door to door in Anchorage, Alaska. Mr. Miller has the support of the "tea party" movement and the backing of former Alaska Gov. Sarah Palin. (Associated Press)
Democratic Sen. Patty Murray is likely to face GOP favorite Dino Rossi in Washington's election for the Senate seat. In recent polls, Mr. Rossi trails Mrs. Murray by about 4 percentage points. (AP Photo)
Sen. Charles E. Schumer, New York Democrat, speaks to reporters off the Senate floor Thursday. He said he hopes a $600 million border-security measure approved Thursday clears the way for consideration of comprehensive immigration-reform legislation.
Sen. Charles E. Schumer, New York Democrat, speaks to reporters on Thursday, Aug. 12, 2010, after the Senate passed a $600 million bill to pay for more law enforcement on the U.S.-Mexico border. (AP Photo/Charles Dharapak)
Members of a joint Senate-House conference on social security get together, Monday, Nov. 16, 1981 in Capitol Hill to discuss the problems of the program. From left are: Senate Budget Director Robert Dole, R-Kan.; house ways and means chairman Dan Rostenkowski, D-Ill. and Rep. Barber Conable, R-N.Y. (AP Photo/John Duricka)